This section provides background information related to the present disclosure and is not necessarily prior art.
Reciprocating compressors typically include a motor and one or more piston-cylinder arrangements. Operation of the motor drives a crankshaft, which imparts a force on each piston via connecting rods to move the pistons within and relative to respective cylinders. In so doing, a pressure of working fluid disposed within the cylinders is increased.
Reciprocating compressors may be used in climate control systems such as heating, ventilation, air conditioning and refrigeration systems (HVACR) to circulate a refrigerant amongst the various components of the climate control system. For example, a reciprocating compressor may receive low-pressure, gaseous refrigerant from an evaporator and compress the refrigerant to a higher pressure. The compressed refrigerant may exit the compressor and flow through a condenser to allow some or all of the refrigerant to change phase from a gas to a liquid. Thereafter, the refrigerant may be expanded via an expansion valve prior to returning to the evaporator where the cycle begins anew.
After being manufactured, compressors often sit idle (e.g., in a manufacturer's inventory or in an installation contractor's inventory) for a relatively long period of time (often several months or more) prior to being installed into and/or operated in a climate control system. Furthermore, compressors sometimes sit idle for long periods of time between periods of operation (i.e., when the climate control system is shut off for a prolonged period of time). As a result, lubricants applied to various moving components of the compressor during assembly of the compressor can, over time, drip off of various components and settle in the bottom of the compressor. Furthermore, during such prolonged idle periods, refrigerant from throughout the climate control system can migrate into the bottom of the compressor, which can hinder lubricant flow through the crankshaft at initial startup of the compressor. Therefore, a compressor that has been sitting idly for a relatively long period of time before initial installation and/or initial operation or a compressor that has been sitting idly (i.e., shutoff) for a relatively long period of time between periods of operation can have moving components that are under-lubricated (i.e., having no lubricant or not enough lubricant) at the initial startup of the compressor, which can cause damage to the compressor. For example, interfaces between the connecting rods and the crankshaft of the compressor can be particularly susceptible to such under-lubrication, which can lead to a seizure of the connecting rods and crankshaft. Such a seizure can catastrophically damage the compressor.